The present invention relates to an adjustment mechanism that adjusts an inclination and a position of an optical axis of an optical system.
It is known that a body tissue is excited and emits a fluorescence when irradiated by light of a specific wavelength. An abnormal body tissue having a lesion such as a tumor or a cancer emits a weaker fluorescence than a normal body tissue does. Such reaction is also performed by a body tissue under a body cavity wall. Accordingly, an endoscope system that detects an abnormality in a body tissue under a body cavity wall utilizing such reactive phenomenon has recently been developed. Such an endoscope system is disclosed in, for example, U.S. Patent Application Publication No. 2002175993A1 and U.S. Pat. No. 6,602,186.
Functions of such endoscope systems include, in addition to a basic observation mode of simply emitting visible light from a tip of the endoscope to illuminate an internal area of a body cavity, a special observation mode of alternately emitting from the tip of the endoscope a visible light and an excitation light for exciting a body tissue under a body cavity wall.